Thermal conductivity k is a measure of the ability of a material to conduct heat (Fig. P7-14). For conduction heat transfer in the x-direction through a surface normal to the x-direction. Fourier's Ian of heal conduction is expressed as
where
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Fluid Mechanics: Fundamentals and Applications
- The topic of total derivation is mathematicsarrow_forwardUse for the ice? List all sumptions. 1.4 Consider axial flow of water in a cold tube. Write the heat conduction equation for the ice forming axisymmetrically on the inside surface of the tube. ice water 1.5 Consider two-dimensional conduction in the semi-circular cylinder shown. The cylinder is heated with uniform pe here to search 05:48 A qu) * ENG r-ny-E/-F hparrow_forwardA random daily consisting of so electrical circuits Used to manufacture an ele ctrononic device for a periad of 20 daye, and a fter examining Them, the mumber of defective circuirts for each day wa as follows: meas urements X4 X2 Xs XS 1-04 1.01 o-981-021-00 2 1-02 0-97 0-96 1-01 \-02 3 1.01 1-07 0-99 1-031.00 46-98 0-97 1.02 0.98o.98 5 0-99 1-03 0-98 1-02|1.01 6 -02 0.9S|1-041.02 0o-95 71.00 0-991.01 1.02 1-ol 0.99 1-02 1-001.041-09 9 1.03 1-040-99 1-02 0-94 101.02 0-981.00 0.99 0.02 terms of the specific control a) for the mean and bi for the range 8arrow_forward
- Consider a wall of thickness 50 mm and thermal conductivity 14 W/m.K, the left side (x-0) is insulated. Heat generation (q) is present within the wall and the one dimensional steady-state temperature distribution is given by T(x) = ax +bxtc [°C] , where c 200 °C, a = -1285 °C/m , b=needs to he determined, andx is in meters. What is the heat fluxes at the right side, x = L, (kW/m )? 9, K 4L) Insulationarrow_forwardConsider a wall of thickness 50 mm and thermal conductivity 14 W/m.K, the left side (x-0) is insulated. Heat generation (q,) is present within the wall and the one dimensional steady-state temperature distribution is given by T(x) = ax +bx+c [°CJ, where c 200 °C, a = -1144 °C/m is the heat fluxes at the right side, x L, (kW/m)? b= needs to he determined, and x is in meters. What 9, K 4L) Insulationarrow_forwardA house wall is composed of 3 layers in series to each other. There is an Aluminum layer that is 4 cm thick, Copper layer that is 6 cm think and Gold layer that is 3 cm thick. What is the total conductivity of the wall and its R-value in units of ft2.F.hr/Btu? [KAl = 2.37 W/cm.C, KCu = 4.01 W/cm.C, KAu = 3.17 W/cm.C]arrow_forward
- Completely solve and box the final answer. Write legibly 1. How much heat will be transferred in KW if a hot gas at 175ºC crosses a wall 100-mm thick and cross-sectional dimensions of 25 cm x 52 cm. It leaves the wall at 52ºC. The thermal conductivity of the wall is 12.4 W/m-ºK?arrow_forwardConduction Heat Transfer X material (a) material (b) . both (a) and (b) have the same thermal conductivity the temperature distribution is independent of thermal conductivity it's not that simple 9. Fin efficiency is defined as: • tanh (mL) (hP/k Ac)1/2 (heat transfer with fin) / (heat transfer without fin) (actual heat transfer through fin) / (heat transfer assuming all fin is at T = Tb) (Tx=L-Tf)/(Tb-Tf) 10. For an infinite fin, the temperature distribution is given by: (T-Tf)/(Tb-Tf)= e-mx. The heat flow through the fin is therefore given by: k (Tb-Tf)/L ● zero, because the fin is infinite ● infinite because the fin is infinite ● (Tb-Tf) (hP/k Ac)1/2 ● (Tb – Tf) (h P / k Ac)1/2 tanh (mL) 11. The Biot number, Bi, is defined as: • Bi=hk/L • Bi=hL/k • Bi= k/LH • Bi=qL/k • Bi=p UL/k 12. For a plate of length L, thickness, t, and width, W, subjected to convection on the two faces of area L x W. What is the correct length scale for use in the Biot number? . L ● W ● t • t/2 • L/2 13. If Bi…arrow_forwardLet's assume that the outdoor temperature in your region was 1 C on 26.12.2002. Let's assume that you use a 2088 W heater in the room in order to keep the indoor temperature of the room at 20 ° C. In the meantime, a 68 W light bulb for lighting, a computer you use to solve this question and load it into the system (let's assume it consumes 217 W of energy), you and your two friends (three people in total) are in the room to assist you in solving the questions. A person radiates 45 J of heat per second to his environment. When you consider all these conditions, calculate the exergy destruction caused by the heat loss from the exterior wall of your room.arrow_forward
- The variables do not vary with respect to time is called as а. Static characteristics O b. Dynamic characteristics O c. Random Error d. Systematic Errorarrow_forward1. The general form of linear second-order differential equation can be written in the form: و بار / كلية الهندسة Q4)/ grap dy q(x)y = r(x) d'y +p(x) dx dy b. dx - F(x)y = F(x) x2 dy dx - xy = C. d. r2 d?y dx2 -f(x)y = F(x) 2431)(5-1) 3 (3-21)2 a. (221 -91i) / 169 b. (21 + 52i)/ 13 c. (-90+220i)/169 d. (-7+17i)/ 13 2. Simplify: الحدار المك المراغة 3. If the roots of second order differential equation is complex conjugate, then the gene contain: a. sinusoidal functions and exponentials b. constant and two exponentials c. two constants and two exponentials d. two constants and one exponential 5 4. The order and degree of the differential: 3(3 - + 4y = sinx* are: d²y a. First-order, First-degree- b. First-order, second-degree Second -order, First -degree d. Second -order, second-degree dx2 lo - 2i tisi. 8- 12i 5. The particular solution of (D² + 4)y = cos 2x is equal to: a. sin 2x b. cos 2x 13+159 C. 4 cos 2x d. 4 sin 2x 5-12 lo Best wishes الامتحانية د. مازن ياسین عبود رئيس القسم بن فاضل…arrow_forwardJes 1:01 i docs.google.com/forms what is the Physicists recognize four fundamental forces.* Flectrical force O - Gravitational force -Strong nuclear force Weak nuclear force O -Muscular force Force of friction Ff is described by • Ff = µN * O p synovlal fluld in the Joints P -coefficient of fraction between two surface in The temperature of the human body is normally about 98.6°F.calculate the temperature of the body "C* oC = (5/9)x(oF-32) =5/9(98.6- 32)-37 oc oc=(9/5)x(of -32) =9/5(98,6-32) =13,3 Under resting conditions the body energy is being used as follows * O 27% by the liver and splee O 20-%by the skeletal musules Under resting conditions the body energy is being used as follows. O 19% by the brain. 15% by the kidney. We can write the first law of thermodynamics as: * O AU-AQ -A.. O AU-AQ +AW. 1kcal = J O 1 Kcal =4184j. O O O Oarrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning